Piezoelectric lighter becomes more and more popular because of its convenience and neat appearance. FIG. 1 illustrates a traditional piezoelectric lighter 10 which comprises a casing 11 having a liquefied gas storage 111 and a piezoelectric unit casing 12 provided on top of the liquefied gas storage 111 and defining a pusher cavity 121 therein. A gas ejection nozzle 13 appears from a ceiling 112 of the casing 11 and communicating with the liquefied gas storage 111 for controlling the flow of gas. A piezoelectric unit 20, which is fitted in the piezoelectric unit casing 12, comprises a movable operating part 21 extended through the pusher cavity 121 for generating piezoelectricity, and an ignition tip 301 connected thereto. A thumb-push cap 15 is slidably fitted in the pusher cavity 121 of the casing 11 in a vertically movable manner, wherein a top portion thereof is exposed above the casing 11 and attached to a top head 211 of the piezoelectric unit 20.
The thumb-push cap 15 is operatively connected both to the gas ejecting nozzle 13 and to the piezoelectric unit 20 for striking spark in response to a push to the thumb-push cap 15. A push-down action of the thumb-push cap 15 will downwardly drive and press the piezoelectric unit 20 which will generate striking spark through and out the igniting tip 301 towards a gas ejection tip 131 of the gas ejection nozzle 13 which is simultaneously operated to release gas by a gas rod activator 14. The ejecting gas ejected from the gas ejection nozzle 13 will be ignited by the striking spark emitted from the ignition tip 301.
For protecting the safety and benefit of children, the U.S. Consumer Product Safety Commission imposed an important regulation that "Child below 5 years old cannot light the lighter". Some of the piezoelectric lighters, such as U.S. Pat. Nos. 4,786,248, 4,859,172, 5,240,408, 5,368,473, 5,462,432, and 5,829,963, each provides a switching mechanism or safety lock mechanism for rendering the piezoelectric lighter child resistant. Some switching mechanisms generally provide a switch member in the lighter body that requires the adult user to turn on before permitting an thumb-operated piezoelectric unit to be depressed to lift a gas pipe to open a gas release valve to emit gas and to generate sparks at the same time to ignite the emitted gas. Other switching mechanisms construct a locking switch for blocking the downward movement of the pusher cap so as to lock up the piezoelectric lighter.
However, such conventional piezoelectric lighters with switching mechanism also bear the drawbacks as follows:
1. Some switching mechanisms require the piezoelectric lighter to alter its structure in order to equip with the switch member. Or, numerous of additional elements of the switching mechanism are required to incorporate with the traditional piezoelectric lighter for ensuring the safety feature thereof. Such costly switching mechanism not only increases the cost of the lighter, but also increases the manufacturing procedures of the lighter.
2. If the user forgets to turn off the switch member to its locking position, the piezoelectric lighter is already to ignite by any child. In other words, such switching-type safety piezoelectric lighter can provide safety function if and only if the adult user remembers to operate an additional turning off action to re-lock the switching mechanism of the piezoelectric lighter again. Most users may even intentionally skip this re-locking operation.
3. There are many kinds of piezoelectric lighter, in which each of them contains a specific casing design. In other words, each style of piezoelectric lighter needs a particular design to incorporate a switching mechanism or safety lock. That would be a costly and troublesome burden to all lighter the manufacturer. Every new design of piezoelectric lighter, the engineer needs to redesign a new specific safety mechanism therefore in order to fit the different shape and structure of the new design of the lighter casing. Especially, to those manufacturers who already have many kinds of piezoelectric lighter without safety mechanism, they need to invest a great expense for preparing new molds.
In fact, the conventional switching mechanism of the piezoelectric lighter is a manual lock only but can not be classified as a safety lock because a real safety lighter should normally be locked, that is the piezoelectric lighter should automatically re-lock after each ignition operation, so as to prevent the children from igniting the lighter anytime, or to prevent the lighter from accidentally or unintentionally be ignited by the user.